A range of studies of the biochemical and biophysical bases for neural transmission systems and cancer chemotherapy is proposed. Specifically, one investigation of neurotransmitters concerns itself with analysis of the active sites of brain enzymes with a view toward design of inhibitory analogs. The same approach is predicated to apply to enzymes implicated in anti-tumor activity. Another neurotransmitter study, focusing on motor systems, predicts the energetically preferred conformations of cholinergic compounds, including nicotinics and muscarinics. Still a different facet of transmission is tackled with a model for ion transport near membranes. Intercalation is the object of one project exploring the interaction of carcinogens and nucleic acids. Yet another effort directs itself to examination of the potential energy hyperspace surrounding the enzyme-substrate complex. A variety of techniques, appropriate to the particular studies, include quantum theoretical and classical potential functions to determine conformational energies and Monte Carlo methods to calculate thermodynamic properties. All these studies depend upon a tool, interactive graphics, which raises insight by providing new techniques in handling structures and new dimensions in the presentation of data. Finally, it supplies a computer environment where the languages are no longer those of artifice, but of English and scientific symbols.